Needle positioning mechanism for sewing machines



March 1966 J. M. MEDYNSK] ETAL 3,237,579

NEEDLE POSITIONING MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet 1 FiledMay 29, 1965 BY Jam /1- #104011 March 1966 J. M. MEDYNSK] ETAL 3,237,579

NEEDLE POSITIONING MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet 2 FiledMay 29, 1963 Huh FIG.2

INVENTORS 6 1 A nsk'f March I, 1966 J. M. MEDYNSKI ETAL 3,237,579

NEEDLE POSITIONING MECHANISM FOR SEWING MACHINES Filed May 29, 1965,

3 Sheets-Sheet 5 FIG.5

INVENTORS TTORNEY United States Patent 3,237,579 NEEDLE POSITIONINGMECHANISM FOR SEWING MACHINES Joseph M. Medynski, Ramsay, and John M.Medynski,

Oakland, N.J., assignors of fifteen percent to Victor M.

Helfand, New York, N.Y.,

Filed May 29, 1963, Ser. No. 284,210 8 Claims. (Cl. 112-219) The presentinvention relates to an improvement in sewing machines; especially to animprovement in sewing machines intended for industrial use, and moreparticularly 'to the provision of an improvement in such sewing machineswhereby the needle bar of the machine will always be disposed in thesame predetermined position, whenever the operation of the sewing headis stopped. This application is a continuation-in-part of our pendingapplication, Serial No. 273,181, filed April 15, 1963.

In performing the sewing operation, especially in in-l dustrial sewing,a great deal of time is wasted by the operator of the machine when hestops the operation of the sewing head in order to remove and replacethe work on the machine. To be able to remove the work and to replaceit, the work must be free of the needle, and, to that end, the needlebar must be in its retracted or uppermost position. As, in the greaternumber of instances the needle bar will not end up in the required, workfreeing position when the sewing machine head is halted, the operator isrequired, in most instances, to adjust the machine to raise the needlebar to the desired position by the slow, manual procedure of turning thefly-wheel of the sewing machine head until the needle bar is movedsufficiently to free the needle from the work. This relatively slow,manual adjustment consumes a great deal of the operators time and addsmaterially to the labor costs of the article on which he is working.Also, where the operator works on a piece basis, it can cut materiallyinto his earning capacity.

It is the object of the present invention, therefore, to provide asewing machine of the character described having a mechanism forautomatically moving the needle bar to uppermost, work-freeing position,each time the operation of the sewing machine head is halted.

It is another object of the present invention to provide a needle baradjusting mechanism for a sewing machine, of the character described,which is powered by the motor of the sewing machine proper, and isautomatically electrically controlled by the same movement that haltsthe sewing machine head operation.

It is also an object of the present invention to provide a needle baradjusting mechanism for a sewing machine, of the character described,which is of relatively simple and sturdy construction and may be readilyinstalled on the machine; is simple and easy to operate and control; andis reliable in its operation.

The foregoing and other objects and advantages of the sewing machine ofthe present invention will become more readily apparent to those skilledin the art from the embodiment thereof more or less diagrammaticallyshown in the accompanying drawing and from the description following. Itis to be understood, however, that such embodiment is shown by way ofillustration only, to make the principles and practice of the inventionmore readily comprehensible, and without any intent of limiting theinvention of the specific details therein shown.

In the drawings:

FIG. 1 is a front, elevational view of the material portion of a sewingmachine embodying the present invention;

FIG. 2 is a fragmentary rear elevational view of the sewing machine ofFIG. 1; with the sewing head omitted;

FIG. 3 is an exploded view of the sewing machine head 3,237,579 PatentedMar. 1, 1966 driving and needle bar positioning mechanism of theinvention;

FIG. 3a is a fragmentary, sectional view diagrammatically illustratingone form of the overriding clutch means for use in the main drive of thesewing machine with the overdrive thereof.

FIG. 4 is a fragmentary view, on an enlarged scale, taken on line 4-4 ofFIG. 1, showing a pedal-actuated switch in the electrical circuit of theneedle bar positioning mechanism;

FIG. 5 is a schematic view of the electric circuit of the needle barpositioning mechanism of the invention.

Referring now in greater detail to the embodiment of the inventionillustrated in the drawing, the same show a sewing machine of oneconventional type frequently used in industry, which includes the sewingmachine head, generally designated as 10, mounted on the work table, 12,and having the continuously running electric motor, 14, supported fromthe underside of the table as on brackets 15, and provided with thedriving shaft 16, carrying a clutch member or disc 18, at its end.

The sewing head 10 includes the main shaft 20, carrying a driving pulleywheel 22, and the vertically reciproble needle bar 24, operativelyconnected to shaft 20 by the lever 26, and the reciprocating arm 28,connected to shaft 20, in the conventional manner.

Motor shaft 20 -is intermittently operatively connectible to the motor14 by a clutch-driven system which includes the driven shaft 30, whichis rotatably and axially slidably journalled, coaxially with shaft 16,in spaced bearings 32, at the end of bracket 34, dependently secured onthe underside of table 12. Driven shaft 30 carries a pulley wheel 36, atone end, which is connected by belt 38 to the sewing head pulley wheel22, and carries at its other end a clutch member or disc 18a, which maybe moved to contact cooperating clutch member 18 on shaft 16 by axialdisplacement of shaft 30. Engagement and release of the clutch may beeffected by means of a rocker arm 40, pivotally supported on extension42 of bracket 34, whose one forked end 44, engages over a pin 46, setinto shaft 30, between bearings 32, and whose other end is pivotallyconnected to one end of a rod 48, whose other end is pivotally securedon the rear or inner edge of a treadle, 49. The rocker arm 40, rod 48and treadle 50 are so arranged that depressing the rodoonnected edge ofthe treadle will displace shaft 30 toward the motor and close theclutch, to operate the machine head 10, and the elevation of the rearend of the treadle will release the clutch, to stop operation of thesewing head 10.

It may be here stated that the foregoing is descriptive of only oneconventional form of a clutch-drive sewing machine for which the needlebar positioning mechanism of the invention may be adapted. Suchmechanism includes a secondary or overriding clutch-drive system for therelatively slower, limited rotation of the shafts 30 and 20, and is setinto operation upon the release of the clutch of the main drive systemto rotate the shaft 20 from whatever position in may have been at on theinactivation of the main drive system, to the position where the needlebar is in predetermined position, as in the uppermost position.

Such secondary or overdrive system includes a secondary driving shaft50, journalled in spaced brackets 15, and is rotated, preferably atlower speed, from the motor drive shaft 16, as by the relatively largepulley wheel 52, carried on shaft 50, which is connected by belt 54, tothe relatively smaller pulley wheel 56, carried on shaft 16. Shaft 50also carries a clutch member or disc 58 at one end. The overdrive systemalso includes a driven shaft, 60, rotatably and axially slidablyjournalled, coaxially with shaft 5@ in spaced bearing 62, on the end ofbracket 64, depending from table 12. The shaft 60 carries on its endfacing shaft a cooperating clutch member or disc 58a, and at its otherend a relatively small pulley wheel, 68, which is connected by belt 79,to a relatively larger pulley wheel 72, mounted on shaft 343 for idlingwhen the latter is rotated by the motor shaft 16 and for engaging it forrotation with shaft 60 when the main drive clutch is released as byratchet means or by an overriding clutch, more or less diagrammaticallyillustrated at 73, in FIG. 3, in a manner well known to persons skilledin the art and through necessary to be specifically illustrated. It mayhere be stated that instead of the toothed pulley wheels and toothedbelts for connecting the shafts of the overdrive with the shafts of themain drive, especially for connecting shafts 60 with shaft 30, ratchetwheels and a ratchet chain may be used.

The overdrive shaft 60 may be axially displaced into and out of clutchengaging position by means similar to that used in the main drive;namely, by a rocker arm 74, pivoted on extension 76, of bracket 64. Therocker arm 74 may have a forked end which engages over the pin 78, setinto shaft at; between bearings 62 in which it is slidably journaled.The other end of the rocker arm 74 may be tilted to slide shaft anaxially toward and away from shaft 50. To effect such tilting, the otherend of rocker arm 74 is connected to a rod 80, which is connected to orcontinuous with the armature of a solenoid 82. The solenoid 82 isconnected in an electric circuit in such manner that when the circuit isclosed and the solenoid is activated, rod 80 will be moved to tilt therocker arm 74 in a direction for sliding shaft 60 into clutch engagingposition, and, conversely, when the circuit is broken through solenoid82, rod 80 will move to tilt rocker arm 74 in a direction to displaceshaft 60 into clutch releasing position.

The electric circuit of the overdrive system may include a normally openswitch which is operated to close the circuit through solenoid 82,either automatically, by the movement of the machine mechanism todisconnect the transmission from the motor 14 to the sewing head shaft22, as by the movement of the mechanism releasing the clutch of the maindrive, as treadle 49; or by a separate, substitute or alternatemechanism that may be actuated by the operator at the same time, orimmediately before or after operation of the treadle. The circuitthrough the solenoid 82 also includes a switch associated with thesewing head shaft 22 which is closed at all times, except when the shaft22 is rotated to the position where it holds the needle bar 24 in thedesired, predetermined position, as in the uppermost position; at whichpoint such switch is automatically opened to break the solenoid circuitand thus release the overdrive clutch 58 and stop the operation of thesewing head at the instant that the needle bar is in predeterminedposition. The latter switch may, preferably, be in the form of a rotaryswitch, designated as 84, of a type well known in the art and notthought necessary to be shown in detail, which may be mounted over theend of shaft of the sewing head.

For treadle actuation, the normally open switch of the solenoid circuitmay be a mercury type switch 86, having the tilting arm or control pin88. The switch 86 is preferably mounted in a frame 90, secured to theend of rocker arm 40, with the pin 88 tilted by gravity into switchopening position. The treadle rod 48 passes through the bottom of frame90 and is provided, in the portion thereof disposed within the frame,with a shoulder 92, arranged to engage and tilt pin 88 into switchclosing position when rod 48 is moved upwardly to clutch releasingposition. A collar 94, is mounted on rod 48, immediately below frame 90,arranged to engage the frame to move it upwardly with rod 48 to completethe movement of tilting rocker arm 40 to release clutch 18.

It may here be stated and it will be readily understood that where theclutch of the main drive shaft is controlled by the knee acting on aknee plate, in the manner well known in the art, switch 86 or a similarswitch may be arranged to be actuated by the movement of such kneeplate, in a manner that will be readily understood by and be clear tothose skilled in the art and not thought necessary to be specificallyillustrated.

It will be clear that while the main drive or transmission is connectedto the motor and the sewing is in operation, the secondary transmissionor overdrive will remain idle and stationary, for the reason that itsclutch 58-58a is open. This is made possible by the fact that pulleywheel 72, which is connected to driven shaft 60 of the overdrive, isfree wheeling or idling. When switch 86 is closed as by movement oftreadle 49 to release clutch 18-18% overdrive clutch is engaged and itsdriven shaft 60 is rotated. Since shaft 60 rotates at lesser speed thanshaft 30, pulley wheel '72 will still idle. When upward movement of rod48 is completed, clutch 1848a is released and shaft 30 disconnected frommotor 14. It will then be driven by shaft 60, through pulley wheels 63and 72, the latter no longer idling, to rotate at a relatively lowspeed. Shaft 30 will, in turn, rotate sewing head shaft 20. If switch 86is closed at the instant when shaft 20 is holding the needle bar 24 inpredetermined position, rotary switch 84 will then be open, the circuitthrough solenoid 84 will remain open, and the overdrive, whose action isnot then needed, will remain inactive. However, if, when switch 86 isclosed when shaft 20 is at any other position, switch 84 will be inclosed position and the circuit; through the solenoid will be completed,thus activating solenoid 82 and tilting rocker arm 74 to close clutch58-58a, activating the secondary drive to rotate shaft 20, as describedabove, to the point where it will move the needle bar 24 topredetermined position, at which point switch 84 will be automaticallyopened to break the circuit through the solenoid 82 and de-activate itand release clutch 58-58a. It will be understood, of course, that themaximum period of operation of the overdrive will be minimum.

This completes the description of the improved sewing machine of thepresent invention. It will be readily apparent that improvement of thepresent invention provides easy to control, reliable, automatic meansfor positioning the needle bar of a sewing machine in any predeterminedposition each time the sewing machine is stopped. It will also beapparent that, because the mechanism is operated directly from thesewing machine motor, it is of relatively simple, safe and economicalconstruction and convenient to control.

It will also be further apparent that the numerous modifications andvariations may be made in the sewing machine of the present invention,by anyone skilled in the art, in accordance with the principles of theinvention, hereinabove set forth and without the exercise of anyinventive ingenuity. We desire, therefore, the protection of the patentlaws for any and all such modifications and variations that may be madewithin the spirit of the invention and the scope of the claims heretoappended.

What we claim is:

1. In a sewing machine, including a sewing head having a rotary driveshaft, a needle bar operatively connected to said rotary shaft forreciprocation thereby, a motor, a main transmission including a maindriven shaft operatively connected to said rotary shaft and movablemeans releasably operatively connecting said main driven shaft to saidmotor, the improvement consisting of a sec ondary transmission rotatableby said motor at a lesser speed than said main transmission, saidsecondary transmission including a secondary driven shaft parallel tosaid main driven shaft, means interconnecting said driven shafts forrotation simultaneously in one direction, means releasably operativelyconnecting said secondary driven shaft with said motor, and meansoperable by said movable means upon movement thereof to release saidmain driven shaft from said motor to connect said secondary driven shaftwith said motor, and means controlled by said rotary drive shaft forreleasing said secodary driven shaft from said motor upon positioning ofsaid needle bar at a predetermined position.

.2. The sewing machine of claim 1, wherein said means interconnectingsaid driven shafts includes a wheel secured to said secondary drivenshaft and a wheel mounted on said main driven shaft, said last namedwheel arranged to freely rotate on said main driven shaft in onedirection and to engage said last named driven shaft when rotated in theopposite direction, and means operatively interconnecting said wheels.

3. The sewing machine of claim 2, when said first named wheel is oflesser diameter than said last named wheel.

4. The sewing machine of claim 2, wherein said secondary transmissionincludes a shaft supported for rotation in fixed position and meansoperatively connecting said shaft to said motor, said secondary drivenshaft releasably operatively connected to said shaft.

5. The sewing machine of claim 1, wherein said means operativelyreleasably connecting said secondary shaft to said motor is electricallycontrolled and includes a solenoid connected in an electric circuit, anormally open switch in said electric circuit, means closing said switchupon actuation of said movable means for releasing said main drivenshaft from said motor, a normally closed switch in said circuit, andautomatic means actuated by said rotary shaft opening said normallyclosed switch when said rotary shaft is disposed in position holdingsaid needle bar in predetermined position, and means operativelyconnecting said solenoid to said secondary driven shaft for connectingthe same to and releasing it from said motor.

6. The sewing machine of claim 5, wherein said normally closed switch isa. rotary switch actuated by said rotary shaft.

7. The sewing machine of claim 5, wherein said secondary driven shaft isslidably supported, and a pivoted arm is connected to said shaft and tosaid solenoid for movement by said solenoid to move said shaft into andout of connection with said motor.

8. The sewing machine of claim 5, wherein said normally open switch isactuated by said movable means releasably operatively connecting saidmain driven shaft with said motor upon movement of said means into shaftreleasing position.

References Cited by the Examiner UNITED STATES PATENTS 2,517,567 8/1950Hill et al 112-219 2,708,415 5/ 1955 White 112219 2,836,276 5/ 1958Schwab et a1 112--219 3,026,834 3/ 1962 Prentzel 112-219 3,114,340 12/1963 Hedegaard 112219 FOREIGN PATENTS 1,274,781 9/ 1961 France.

820,995 11/ 1951 Germany.

OTHER REFERENCES Schwab: German application, 1,134,266, printed August2, 1962 (Kl 52a 56/04) (2 s'hts. dwg., 2 pp. spec).

FRANK J. COHEN, Primary Examiner.

ROBERT V. SLOAN, JORDAN FRANKLIN,

Examiners.

1. IN A SEWING MACHINE, INCLUDING A SEWING HEAD HAVING A ROTARY DRIVESHAFT, A NEEDLE BAR OPERATIVELY CONNECTED TO SAID ROTARY SHAFT FORRECIPROCATION THEREBY, A MOTOR, A MAIN TRANSMISSION INCLUDING A MAINDRIVEN SHAFT OPERATIVELY CONNECTED TO SAID ROTARY SHAFT AND MOVABLEMEANS RELEASABLY OPERATIVELY CONNECTING SAID MAIN DRIVEN SHAFT TO SAIDMOTOR, THE IMPROVEMENT CONSISTING OF A SECONDARY TRANSMISSION ROTATABLEBY SAID ROTOR AT A LESSER SPEED THAN SAID MAIN TRANSMISSION, SAIDSECONDARY TRANSMISSION INCLUDING A SECONDARY DRIVEN SHAFT PARALLEL TOSAID MAIN DRIVEN SHAFT, MEANS INTERCONNECTING SAID DRIVEN SHAFTS FORROTATION SIMULTANEOUSLY IN ONE DIRECTION, MEANS RELEASABLY OPERATIVELYCONNECTING SAID SECONDARY DRIVEN SHAFT WITH SAID MOTOR, AND MEANSOPERABLE BY SAID MOVABLE MEANS UPON MOVEMENT THEREOF TO RELEASE SAIDMAIN DRIVEN SHAFT FROM SAID MOTOR TO CONNECT SAID SECONDARY DRIVEN SHAFTWITH SAID MOTOR, AND MEANS CONTROLLED BY SAID ROTARY DRIVE SHAFT FORRELEASING SAID SECONDARY DRIVEN SHAFT FROM SAID MOTOR UPON POSITIONINGOF SAID NEEDLE BAR AT A PREDETERMINED POSITION.